NOTE: uvot_fluxes_wget.pl vrs. 2018-01-16 fem at 180704d18h16m17s666078usUT
NOTE: Source region spec. is: 32.66046 69.96408 4"
NOTE: Used archived XRT position of  32.66046  69.96408  4.00
NOTE: position reference is GCN_Circulars-22890

=========== Draft Upper Limit Circular ========

GRB 180704A: Swift/UVOT Upper Limits

S.W.K. Emery (UCL-MSSL) and E. Sonbas (Adiyaman Univ.)
report on behalf of the Swift/UVOT team:

The Swift/UVOT began settled observations of the field of GRB 180704A
3255 s after the BAT trigger (Sonbas et al., GCN Circ. 22885).
No optical afterglow consistent with the XRT position
(Evans et al. GCN Circ. 22890)
is detected in the initial UVOT exposures.
Preliminary 3-sigma upper limits using the UVOT photometric system
(Breeveld et al. 2011, AIP Conf. Proc. 1358, 373) for the first
finding chart (FC) exposure and subsequent exposures are:

Filter         T_start(s)   T_stop(s)      Exp(s)         Mag

white_FC          3255         3404          147         >20.9
white             3255         5455          537         >21.0
v                 4233        10567         1082         >20.0
b                 3618         5253          393         >19.7
u                 3413         5048          393         >19.8
w1                4643         4843          197         >19.5
m2                4438        11190          804         >19.9
w2                4028         9654         1082         >20.4

The magnitudes in the table are not corrected for the Galactic extinction
due to the reddening of E(B-V) = 0.87 in the direction of the burst
(Schlegel et al. 1998).